1. Field of the Invention
The present invention concerns a pneumatic tool.
The present invention is directed to pneumatic tools which comprise a body in which a pneumatic motor is housed, said body having at one end means for connecting it to a compressed air supply hose while the other end is fastened to a tool-holder terminating in an angular part receiving a tool, for example a chuck for gripping a drill bit.
2. Description of the Prior Art
Some screwing, unscrewing, drilling, etc jobs have often to be carried out in inaccessible places and the angular parts can have various shapes, for example bent at 90.degree. or 120.degree. or bent once at 90.degree. and again at 90.degree. . Consequently, a series of pneumatic tools must be made available, according to the nature of the jobs to be undertaken. This is costly and somewhat impractical. A first object of the invention is to solve this problem.
These pneumatic tools usually include a lever articulated to the body and controlling the feed of compressed air to the motor, the body being held against the palm of the hand of the user and the lever being actuated by the fingers. The angular part is very often not suitably oriented relative to the lever for the job at hand and this obliges the worker to contort the hand which is tiring and detrimental to the quality of the work to be done.
The prior art includes U.S. Pat. No. 3,574,374 which is directed to a surgical instrument which comprises a motor element and a tool-holder terminating in an angular part adapted to receive a tool.
The motor element terminates at a bush having axial guide slots and a groove while the tool-holder has at the corresponding end a male part adapted to be inserted into the bush and having a lateral projection adapted to be selectively engaged in a slot of the bush and a ball catch which cooperates with the groove to fix the tool-holder to the motor element.
With an instrument of this kind the angular position of the tool-holder relative to the motor element can be changed, subject to a limitation set by the number of guide slots. Also, modifying the angular position necessarily entails uncoupling the tool-holder and the motor element.
The instrument described in this American patent cannot feasibly provide a U-shaped tool-holder, i.e. a tool-holder in which the part holding the tool is on the same side as the male part adapted to be inserted in the bush, because during use the tool-holder would be uncoupled from the motor element.
One object of the invention is to remedy the drawbacks of the prior art.